1. Field of the Invention
This invention relates generally to the recording and reproducing of a visual image or video signals, and more particularly is directed to the recording and reproducing apparatus in which a visual image or video signals are recorded in successive record tracks on a record medium without guard bands between adjacent tracks.
2. Description of the Prior Art
In existing systems for recording visual image signals or video signals on a magnetic record medium, such as, a magnetic tape and reproducing such signals, successive fields or frames of the video signal are recorded along respective record tracks which extend obliquely across the tape, with guard bands or spaces being provided between the successive record tracks on the record medium so that, when the recorded video signal is being reproduced by a magnetic reproducing head or heads scanning the tracks in succession, the signal being reproduced during the scanning of one of the tracks will not be deteriorated by cross-talk from the signal recorded in the next adjacent tracks. The width of each of the guard bands, or unrecorded spaces, between adjacent tracks is usually selected to be from 60 to 100% of the width of the record tracks with the result that from 30 to 50% of the area of the record medium is wasted, that is, is not occupied by recorded signals. Thus, even in the case of recording video signals on the magnetic tape, a relatively large length of the magnetic tape is required for the recording of each unit period of time of the video signal and, by reason of the inherent limitation of the length of the tape that may be wound on a single reel, the video signal cannot be recorded for a long period of time without interruption. Even more severe limitations are imposed on the length of time during which a video signal can be recorded without interruption when the record medium is in the form of a disc of magnetic sheet material having a spiral record track with the guard bands being provided between adjacent turns of the spiral track, or when the medium is in the form of rectangular sheet of magnetic material having a series of record tracks extending generally parallel to its major axis with guard bands between such tracks, or when the medium is in the form of a very narrow magnetic tape, for example, less than 1/4 inch, with having a series of record tracks extending obliquely across the tape without guard bands between such tracks.
Further, in the existing systems, as described above, it is customary to provide a servo tracking arrangement by which each reproducing head is made to scan accurately along a record track so that the previously mentioned guard bands can protect against the simultaneous reproduction of signals recorded in two adjacent tracks which would cause interference, for example, in the form of a beat signal.